Question

If a solution is saturated, which of these is true?

Answer 1

If a solution is saturated, that means it already posses the maximum number of solutes thus have been dissolved in it, and thus the concentration cannot be increased.

Answer 2

The concentration cannot be increased.

But depending on your level of chemistry, it can be heated with more solute dissolved to create a super-saturated solution after cooling down. But that's not necessary in this question